In order to achieve a more diverse and flexible way of human-machine interaction, in addition to detection of the touch location, the current touch display panel can also detect the magnitude of the force applied on the panel. The detection of the magnitude of the force on the panel can be achieved by a force sensor using the Wheatstone bridge principle. Ideally, the output of the force sensor is 0V, when a force is applied on the panel, the panel deforms, and the resistance of the force sensor changes, then the force sensor outputs a signal value related to the deformation extent of the panel.
However, due to the problem of production process, or the status changes of the sensor itself or the display panel resulting from the heat generation during working, the force sensor will output a signal value even when the panel is not subjected to a force, thereby resulting in the problem of abnormal force detection.